1. Proteins

2. Proteins Numerous functions in the human body.
Contain carbon, hydrogen, oxygen and nitrogen (and sulfur in some cases)
Compose 12 to 18% of the lean adult human body
More complex than lipids and carbohydrates
Largely for structure of body tissues
Largely responsible for metabolism
Examples: enzymes, motors, pigments, antibodies, some hormones, ETC!!!

3. Amino Acids Amino acids are the building blocks of proteins
Amino acids are joined together to form dipeptide, tripeptide, peptide and polypeptide chains
This is the first level of organization of proteins
There are 20 (22 in babies) amino acids that the human body uses to make proteins (almost always the “left handed” versions)
12 of these can be synthesized by the human body
8 must obtained from other sources, these are the ESSENTIAL AMINO ACIDS

4. Amino Acids
There are common portions to amino acids. -Amino Group -Carboxyl broup -Hydrogen (side) -Side group

5. Amino Acids
Amino acids link together at the carboxyl groups and the amino groups to form peptide bonds.
This is the first (primarily level of organization:

6. Levels of Organization
Secondary Structure:
Tertiary Structure:
Quaternary Structure:

9. Enzymes “Biocatylists”
They are the same at the beginning of a reaction as they are at the end of a reaction. They don’t get used up in the reaction.
They lower the activation energy of reactions
They speed reactions up as much as 10 billion times
Usually consist of 2 components:
-Protein component: apoenzyme
-Nonprotein component: cofactor
-May be a metal ion
-May be an organic substance (like a vitamin), then called a coenzyme

10. Activation Energy

11. Activation Energy

12. Enzymes
Enzymes are highly specific, each will bind with only a specific substrate. They bind at the active site, which has a characteristic shape unique to that enzyme enzymes known in the human body.
Many enzymes fit like “lock and key,” others will bend somewhat at the active site to produce an “induced fit.”
Enzymes are highly efficient. Some enzymes will act on as many as 600,000 molecules in a second.

13. Enzymes Subject to a variety of cellular controls
Chemical environment of the cytosol of a cell (such as pH, etc.) will often be that factor.
-The chemical factors can change the forms of the enzyme from an
active to inactive form and vice versa.
-These chemical factors are often under the control of the genes of
cells

14. Catalase

15. Enzyme Action